Adjustable bit



T. G. DOYLE.

ADJUSTABLE BiT.

APPLICATION HLED NOV-17I 1920.

Patented Nov. 22, 1921.

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INVENTOR m N M A PATENT OFFICE.

THOMAS GREGORY DOYLE, OF FALL RIVER, MASSACHUSETTS.

ADJUSTABLE BIT.

Specification of Letters Patent.

Patented Nov. 22, 1921.

Application filed November 17, 1920. Serial No. 424,669.

To all whom it may concern:

Be it known that I, THOMAS G. DOYLE, a citizen of the United States, and a resident of Fall River, in the county of Bristol and State of Massachusetts, have invented a new and Improved Adjustable Bit, of which the following is a full, clear, and exact descrip tion.

This invention relates to improvements in adjustable bits, an object of the invention being to provide a bit with an adjustable bar carrying the spur at the operating end of the bit and secured in its position of adjustment by means of the same screw which is utilized for securing the cutting plate at its proper adjustment.

A further object is to provide a bit having removable spurs, one of said spurs constituting a portion of the cutting plate and the other of said spurs removably clamped against the bit by means of the securing means of the cutting plate.

A further object is to provide a bit which, because of an improved construction and arrangement of removable parts which can be cheaply and conveniently replaced, will result in an economy to the user and lengthen the life of the bit to the maximum degree.-

IVith these and other objects in view the invention consists in certain novel features of construction, and combination and arrangements of parts as will be more fully hereinafter described and pointed out in the claims.

In the accompanying drawings- Figure 1 is a view in front elevation of a bit embodying my invention.

Fig. 2 is a view in section on the line 22 of Fig. 1.

Fig. 3 is a view in rear elevation.

Fig. 4 is a view in transverse section on the line 41 of Fig. 1.

1 represents the shank and 2 the body or head of my improved bit. This body or head 2 is formed with an integral screw 3 at one end and with a projecting lip at such as is customary in the art. A cutting plate 5 is adjustable transversely of the head, is provided at its outer edge with a spur 5, and secured in place by a clamping plate 6 having an overlapping wall 7 which bindsthe cutting plate, and a screw 8 is projected through an opening 8' and screwed into a threaded opening 9 in the body or head 2 to clamp the plate 5 against any position of adjustment. This form of cutting plate and securing means is common in the art, and hence, I do not wish to be limited to the exact construction and means of operating the same except in that I employ a screw 8 which serves as a clamping means for the plate 5, and, in addition, performs the function of securing a spur carrying bar 10 at any position of longitudinal adjustment. This bar 10 is movable in a dove-tailed groove 11. in the back of the head or body 2 and has a spur 12 at its lower end. The screw 8 jambs against the bar 10 so that when said screw is in position to hold the adjusting plate 5 against accidental movement, it also functions to bind the bar 10 and secure the latter against movement.

The spur 12 takes the place of the ordinary integral spur on bits such as commonly employed, and by reason of the construction above described, I am enabled to adjust this spur longitudinaly and also replace the same in the event of injury, which will be readily understood.

My invention, therefore, consists broadly in the provision of a spur or spur carrying member which is removable and adjustable and which is secured in its position of ad justment by the same means which is employed to clamp the cutting plate.

Various slight changes might be made in the general form and arrangement of the parts described without departing from the invention, and hence I do not limit myself to the precise details set forth, but consider myself at liberty to make such changes and alterations as fairly fall within the spirit and scope of the appended claims.

I claim:

1. The combination with a bit, of a laterally adjustable cutting plate on the bit, a longitudinally adjustable spur-carrying member mounted on the bit, and securing means operating to secure the plate and spur-carrying member against movement.

2. A. bit having a longitudinal dovetailed groove therein, a bar adjustable in said groove, a spur at one end of the bar, a laterally adjustable cutting plate having a spur at its end, and means for simultaneously clamping the cutting plate and the spur carrying bar.

3. A bit having a longitudinal dove-tailed groove therein, a bar adjustable in said groove, a spur at one end of the bar, a

laterally adjustable cutting plate having a spur at its end, a clamping plate engaging the cutting plate and having an opening therein, said bit having a screw threaded opening registering with the opening in the clamping plate, and a headed screw proj ected through the opening in the clamping plate, engaging the screw threads in the opening of the bit and at its inner end exerting a binding or jamming action against the bar, whereby said screw operates to secure the adjustable parts ofthe bit against independent movement.

THOMAS GREGORY DOYLE. 

